SSL VPN authentication is successful. Using the file sharing function, you can view directories and files, but you cannot upload, delete, and rename files. What are the possible reasons?

Accessing the headquarters server through the IPSec VPN from the branch computer. The IPSec tunnel can be established normally, but the service is unreachable. What are the possible reasons?

On the USG, you need to delete sslconfig.cfg in the hda1:/ directory. Which of the following commands can complete the operation?

As shown in the figure, the firewall is dual-system hot standby. In this networking environment, all service interfaces of the firewall work in routing mode, and OSPF is configured on the upper and lower routers.
Assume that the convergence time of OSPF is 30s after the fault is rectified. What is the best configuration for HRP preemption management?

What are the following VPN protocols that do not provide encryption?